a. Field of the Invention
This invention relates to a remote control device which controls a device such as television camera, etc. to be disposed at a remote distance from an operating table.
b. Description of Prior Arts
There have heretofore been known various types of television camera devices to be remote-controlled on the basis of operating signals from an operating table, most of which are of such type that, when the television camera is to be remotely operated in a plurality of desired modes, such modes are preset on the side of the operating table in accordance with such various modes by the use of a plurality of potentiometers, and, at the time of the remote control operation, these potentiometers are sequentially selected according to the need, the signal from which is used as the remote control signal. Since the potentiometer per se has essentially high resolving power, precision in the control signal per se is satisfactory. However, when the desired modes of control to be set are numerous, number of the potentiometer required should correspond to number of the control mode. Still more, when a plurality of potentiometer is required to define each of the established modes, the number of the potentiometer remarkably increases with the result that correspondence between each of the potentiometers at the operating table and each of the established modes becomes difficult, which has been the main cause for poor operability.
Further disadvantage in the conventional remote control device utilizing such potentiometers is that, when the conditions for each established mode are corrected, the preset values for the mode are destroyed and the established mode cannot be restored.
Explaining in more detail the known type of remote control device for the television camera having such disadvantages, the following six major control elements for the television camera are usual, i.e., panning, tilting, zooming, focussing, aperture (or iris), and camera height (or level). Accordingly, when the television camera is to be controlled by the operating table which is remote from the TV camera, these various kinds of control signals are fed from the operating table to the television camera, and, while watching a monitor at the side of the operating table, the potentiometers are adjusted to regulate each of the control elements of the television camera so that the monitored image may become a predetermined image. In this manner, the television camera is controlled to a desired established mode. In case the established mode is plural, additional groups of the potentiometers are adjusted, and, in the same manner as mentioned above, while watching the image pick-up condition of the television camera, the control signals are fed to the control elements of the TV camera to establish the potentiometer groups. Upon completion of the setting operations of the potentiometers, if the images to be picked up by the television camera are to be sequentially selected on the basis of the established modes of each television camera (this image to be picked up by the TV camera will be called hereinafter "shot"), each potentiometer group may be sequentially selected. In other words, the above-described conventional remote control device for television camera mechanically stores the established modes of the television camera by the adjustment quantity of the potentiometers, based on which stored quantity the television camera is remote-controlled.
In this consequence, when the number of the control elements to define the established modes and each mode is increased, the number of the potentiometer also increases accordingly with the result that there accrue various defects to be enumerated in the following.
(1) the area to be occupied by the potentiometer knobs on the operating table becomes large to make it unable to increase the shot number to a desired extent;
(2) since a great many potentiometers are arranged on the operating table, it is highly difficult to recognize which potentiometer knob corresponds to which control element of the television camera, hence operability of the remote control device is poor;
(3) since each of the control elements is independently remote-controlled by the potentiometer, each control element is driven independently with the consequence that the pick-up image is extremely unsightly;
(4) after adjustment of the potentiometer, when the re-adjustment thereof is effected for correction, the original set position is lost, and it becomes impossible to reproduce the shot of the originally established mode;
(5) since the device is controlled by analog signals, it is impossible to connect the device with an external computer; and
(6) since the set value for each control element is different from one to the other, the operational time for reproduction of each control element, at the time of the shot reproduction, is also different with respect to each control element, hence the image thus reproduced is unsightly.